1. Field of the Invention
The present invention relates to an antenna, more particularly to a multi-band antenna for application to Wireless Local Area Network (WLAN) and World Interoperability for Microwave Access (WiMAX) communication protocols.
2. Description of the Related Art
Conventional antennas are usually not designed to be simultaneously compatible with Wireless Local Area Network (WLAN) and World Interoperability for Microwave Access (WiMAX) communication protocols. Accordingly, multiple antennas are required to be disposed in an electronic device in order to ensure compatibility of the electronic device with WLAN and WiMAX communication protocols. As a consequence, more space is required in the electronic device, thereby affecting adversely the size of the electronic device.
Some Planar Inverted-F Antennas (PIFA) are designed to employ parasitic elements for enhancing antenna coupling that is dependent upon clearances formed among radiator components and a grounding conductor so as to achieve effects of broadband operation. However, it is difficult to control impedance frequency and bandwidth of the antenna. Moreover, efficiency of the antenna is relatively low.